Colt King Cobra 6". Bought one, kept it 3 years, traded it, bought another 4 months later. The snake collection didn't look right without it even though I think they are poor examples of Colt craftsmanship.
"They're just so dang cool! Look, there's a rail for the optic, maybe a laser, oh, and a bipod..."
---time passes---
"Man, what am I gonna use this tricked-out pistol for except a range toy? For Sale! Sold!"
---time passes---
"Well, would ya look at that! Here's the box for that old red dot scope I put on the PLR. Hey, and the old flash hider and a couple of mags! So it wouldn't bo TOTALLY expensive to get another one. Man, was that thing ever fun to tinker with! Wanted To Buy!"
I had a rifle a few years ago that I traded to a friend and then about a year after that I got it back from him in another trade. With handguns I have had a few of the same models but never the same serial #.